In a booster cable holding structure, a resin terminal supporting portion includes a tooth-edge surrounding wall on a pressed surface thereof to be pressed by a plurality of teeth arranged in a width direction of a pressing surface of a clip in a state the clip clamps a clamping connection portion, a wall inner surface of the tooth-edge surrounding wall closely surrounds each edge of at least two of the teeth of the clip or closely surrounds the edges of the at least two teeth together.